Permastone and Formstone: Modern Marvels or the Margarine of Architecture

“Science Finds, Industry Applies, Man Conforms” was the motto of the Century of Progress International Exhibition, also known as the Chicago World’s Fair of 1933. The fair celebrated the centennial of Chicago’s founding, but with the United States in the grips of the Great Depression, the focus was on the future, and the technology that would get the world there. The fair emphasized new ways people could travel, communicate, and live—and how design could express futuristic intentions. One of the fair’s exhibits was the Homes of Tomorrow exhibition, a group of houses with fanciful designs and innovative construction systems like the Armco-Ferro House, a building designed to be reproduced on a mass scale using manufacturing techniques already applied in the automotive industry. The House of Tomorrow, designed by architect George Fred Keck, featured an airplane hangar and central air conditioning.

The Wieboldt-Rostone House, designed by architect Walter Scholer, was a six-room, two-bedroom Mediterranean revival inspired home with an attached garage, and was clad entirely of red-brown Rostone, an artificial stone made of crushed limestone, a hydrate of lime and shale, which was steam “cooked” and formed into molds. Rostone, a product of the R.H.K. Corporation of Lafayette, Indiana, promised economy in materials and manufacture and flexibility in design would come together for a “charming, homelike appearance,” according to a booklet produced by Rostone, Inc., for the exhibition.¹

Nearly 40 million people would see the Century of Progress exhibition, and the Homes of Tomorrow was one of its most popular exhibits. Yet, in the coming decades, millions more would learn of artificial stone by one of many regional aliases, such as Tru-Stone, Stone of Ages, Dixie-Stone, Fiesta-Stone, Bond Stone, Rx Stone, and the two most well-known: the Formstone of Baltimore or the nationwide phenomena of Permastone.

Like Kleenex or Q-Tips, Permastone and Formstone have become genericized trademarks for the same kind of product, a ubiquitous type of cladding material seen on buildings across the country, particularly in places where, in the mid-twentieth century, the commercial and residential building stock needed a modern facelift.

With its vibrant colors, chunky, stonelike appearance, and all-over patterning, Permastone and Formstone trick the eye, fooling you briefly into believing that what you are looking at is real stone, not a mixture of materials formulated and then applied to look like natural stone. Yet its placement on a building seems a bit too fluid for real stone to pull off. Artificial stone clads elements like church steeples or doorways a little too tightly, a little too perfectly. The color of each “stone” is a little too bright. The mortar joints between the stone are a little too shallow. It almost looks too much like stone, like a building material made for a Hollywood backlot, like it is trying a little too hard. This attempt at imitation has furnished Permastone, Formstone, and all the other types of artificial stone seen on older buildings, with a reputation as a material of bad taste. The historical perspective on its application is often riddled in judgement—that those who chose Permastone or Formstone willingly destroyed good old Victorian houses in favor of a fleeting modern trend, because they didn’t appreciate the character of those good old houses, and/or because they themselves were tacky.

Permastone and Formestone’s popularity follows other commercial trends of the 1950s and 1960s that deployed technological innovation to deliver products that looked to emulate the appearance, feel, and even taste of a traditional item on the market that was difficult to acquire, costly, or had a limited serviceable life. Processed foods like Spam and margarine promised to deliver to the public an experience that was similar enough to an old-fashioned country ham, or a rich, creamy stick of butter without worrying about cost or spoilage.

Limestone and sandstone required transport and skilled masons to install, increasing the cost of a building project. Permastone and Formstone offered an economical, convenient solution. Artificial stone follows a basic recipe, made of Portland cement along with crushed quartz, metallic hardeners, mineral colors, and waterproofing agents. Artificial stone could be formed in prefabricated sections manufactured off site, or applied on site while wet with patterns, or formed by hand.

The installation process begins with metal lath or chicken wire, nailed to a surface. Then, like frosting on a cake, mortar would be applied to the surface, first as a scratch coat, then as a skim coat, and then as a topcoat. The topcoat would receive a shape and a rusticated texture, along with approximated mortar joints. When worked freehand with a trowel, Permastone and Formstone “stones” could be formed to almost any shape or size imaginable, meaning it could be applied around doors and window openings, as well as complicated architectural elements like turrets and cornices. Once the material was applied, color and even a glittery sparkle could be added.

The colors and textures of Permastone and Formstone range from realistic stone surfaces, like those found on a rustic old-world castle of native limestone, or cladding looking more like coffee beans or even kitty litter. Color combinations noted in catalogs had names evoking places in the United States where architectural stone was mined, or types of stone, including “Indiana Blend,” and “Sandstone,” but as the product grew in popularity customers began requesting custom colors and custom combinations. Permastone and Formstone could be applied on almost any building type, from a single-family home to a rowhouse, to a funeral home or church, where the traditional look of stone could help convey permanence, dignity, and quality.

For buildings with multiple construction materials or additions over time, artificial stone provided the opportunity to unify the allover surface of a structure, which made it popular as a component for building renovations. Permastone’s and Formstone’s nature allowed for a building owner to use the material to further customize their home or business by adding address numbers, a business name, or the initials of the family or homeowner. The flexibility and convenience of Formstone and Permastone allowed a building owner to choose to cover the whole building, or just a section, such as a façade, storefront, or the entryway of a building.

On May 17, 1937, Louis Albert Knight of Baltimore’s Lasting Products Company, a paint manufacturer, applied for a patent for a “process of making artificial stone wall facings” that included different varieties of stone facing as well as a tool to simulate the texture of natural stone.²

This product, Formstone, began being offered through the Lasting Products Company in 1938, and the company began advertising aggressively in the Baltimore area. By the 1950s, advertisements in local newspapers began featuring Baltimore’s historic rowhouses clad in Formstone. “Yes! Formstone is everywhere!” an advertisement in the Baltimore Sun proclaimed in February 1950, along with a photograph of a freshly covered rowhouse.³ As the popularity of artificial stone grew, so did competitors to Formstone, many of which trained at the Lasting Products Company, with Formstone employees, or were themselves former Formstone employees looking to start businesses on their own.

Doing business out of a two-story building in Columbus, Ohio, adorned, naturally, with a cream-colored version of the product it sold, the Permastone Company, established in 1929, took artificial stone nationwide, providing specialty businesses an opportunity to offer Permastone everywhere, including Texas, Hawaii, and Alaska. By 1957, the Permastone Company was serving over 300 dealers nationwide, providing them with national advertising, as well as sales and technical guidance.⁴ Permastone permitted one local dealer in each area, but like Formstone, the formula and application was easily replicated, particularly as materials and labor were readily available.

Advertisements for Permastone, in local papers as well as national publications like American Home and House Beautiful, emphasized the timelessness of stone as a part of architectural design, but asserted that Permastone made the aesthetics of stone available to more than just the wealthy, but to the masses. “Permastone is actually a stone like jacket—snugly, staunchly encasing the building from the ground up. So flexible in its uses that it can be applied to any type of wall, regardless of its condition,” claimed an advertisement in the Chicago Tribune in 1947.⁵ Humble wood framed, brick, or concrete block buildings could now be clad with a material that could convey sophistication and dignity. For those in US cities like Baltimore, St. Louis, Philadelphia, and Chicago unable to afford to build new homes or access the suburbs but looking to embrace newness, Permastone provided an economical solution, with a “20-year guarantee” and a promise that it would require no maintenance or painting. In Baltimore in the early 1950s, the cost of installation for a two- or three-story rowhouse averaged $600 or $700 dollars, with companies offering payment plans for as little as $7.00 a month beginning 60 days after purchase.⁶ As home renovation loans from the Federal Housing Administration became available to select borrowers, those loans, advertisements claimed, could be used to install Permastone.

Local dealers across the country were offering Permastone. In Baltimore, salesmen would visit neighborhoods on foot extolling the virtues of Formstone. Permastone and Formstone as installed also proved to be a driver in sales as homeowners saw the results with their own eyes. Even the Rostone House would be given the Permastone treatment. At the conclusion of the Century of Progress Exhibition in 1934, the Houses of Tomorrow were moved from Chicago to Beverly Shores, Indiana, where the Rostone House became a private residence. When the exterior material of the Rostone House failed in 1950, it was clad in Permastone.

The collections within the Association for Preservation Technology Building Technology Heritage Library are full of letters written mostly in the 1940s from building owners, architects, real estate brokers, and even local governments extolling the virtues of Permastone.

In 1939, attorney W.O. Wallace of Columbiana, Ohio, wrote to the Permastone Company: “My building, built by the pioneers over 100 years ago out of soft brick and lime mortar, was in bad condition. Various attempts have been made toward repairing and preserving the walls, including pointing, paints and finally stucco, which failed after a short time. Upon your assurance that Perma-Stone would really last, I granted you the job and now after three years, I am fully satisfied that Perma-Stone is as you represent it.”⁷

“It also went through the earthquake of 1935 that completely demolished a building that stood within 100 feet of the office with no damage whatsoever,” shared real estate broker A.C. Yingling from Long Beach, California, in 1947.⁸ In 1949, the building committee of the Second Christian Reformed Church of Roseland in Chicago wrote to the Permastone Company, “The beautiful ‘Light Limestone’ blend of Perma-Stone recently applied to our 55 year old frame church building has improved the appearance beyond our fondest expectations.” At the end of the letter, a postscript, “We wish to add that the appearance of the stone, after almost a full winter, is fresh as ever and it seems that the dirt and grime of the city does not adhere to it.”⁹ While the Second Christian Reformed Church is long gone, the building in Roseland remains and is still clad in the Permastone Company’s “Light Limestone.”

Permastone and Formstone claimed it could be affixed to any type of wall surface or type of building, from brick to wood framing to cinder block, regardless of condition. Its application did not require the condition of the existing wall surface to be examined. While many Permastone and Formstone buildings remain sound today, the poor condition of materials beneath Permastone would inevitably cause the new material to fail. Coupled with other building renovations, particularly the removal of the kind of Victorian architectural elements that building owners and homeowners believed at the time to be old fashioned, often caused the areas around these elements to be improperly sealed, introducing moisture into the wall and causing the façade to fail from within. Some ad hoc artificial stone applications used non-galvanized nails and lath that would rust underneath the wall surface or would apply the material directly to the façade surface. All these variables caused the companies that offered Permastone and other artificial stone cladding to withdraw from pushing the product by the late 1960s. Companies that dealt exclusively in artificial stone, like Formstone, closed in the late 1960s as well, unable to keep up with the ultimate impermanence of the product or any of its claimed guarantees.

The conclusion of the Permastone and Formstone cladding craze corresponded with a rise in the interest in preserving the United States’ historic architecture. In the late 1960s and early 1970s, cities across the country were taking stock of historic buildings, codifying preservation ordinances and creating local historic districts. Homeowners were purchasing cheap property in older urban neighborhoods and looking to restore those properties back to their original appearance. Neither of these scenarios included Permastone or Formstone. Historic Preservation Commissions generally took an exclusionary stance on Permastone, that its presence meant that a building was too altered to be included in discussions of what was worth preserving. Rehabbers were looking for ways to remove artificial stone, largely unable to determine if the wall system underneath was viable, or if the condition of the building as a whole would be better or worse off without it. Permastone and Formstone proved just as complicated to install as it was to remove. Using a masonry saw, the concrete material along with the lath would be removed first, in large sections, followed by the anchor nails. If the nails were affixed to a brick wall through the bricks as opposed to the mortar joints, which happened frequently, damaged brick would need to be repaired. The removal of Formstone and Permastone often led to brick surfaces that were scratched and distressed, and original decorative features like projecting string courses and window lintels chiseled off to allow for the material to be installed as close as possible to the facade without bulges.

An issue of The Old House Journal from 1982 addressed Formstone and Permastone in an article titled “Unmuddling...Removing Formstone & Other Indignities” by Ron Pilling. The article cautions “When you remove Formstone, you’ll find that you’ll also have to repair the uncovered masonry surfaces. This is not a weekend job, but it is certainly within the realm of a serious and ambitious restorationist.”¹⁰ The same article acknowledges a tension in terms of the way in which preservationists must acknowledge that the passage of time affects its relationship with materials. “We know that there are some preservationists who won’t like this article. They’ll say Formstone is a part of the history of a building and therefore should not be disturbed.”

As a function of government, preservation has been slow to apply the type of narrative that Permastone and Formstone conveys into policy. But the culture of the appreciation of history through all parts of the built environment, particularly in Baltimore, has embraced it. Little Castles: A Formstone Phenomenon, a 1998 short film directed by Skizz Cyzyk and Lillian Bowers, interviewed Formstone building dwellers, preservationists, and Baltimore-born filmmaker John Waters. An arbiter of tastes both tacky and tasteful, Waters proclaimed that “to me a Formstone building with an Infant of Prague in the window and painted screens is bizarre, but it isn’t at all to the people that live there. They would think my house is bizarre.” In 2002, HBO viewers were introduced to The Wire, a show that explored commerce in Baltimore, both legal and illegal, through the lives of characters that ranged from statewide politicians to law enforcement officers to blue collar workers to street level drug dealers. The Formstone rowhouses and vernacular architecture of Baltimore were featured prominently throughout the five seasons, which, with the availability of streaming services, introduced a whole new audience to the show, and to the local flavor of Formstone. In May 2024, Visit Baltimore unveiled a mobile visitor center, complete with a faux façade of Formstone-clad rowhouses.

In Baltimore, the Commission for Historical and Architectural Preservation now allows both the removal of Formstone from historic façades, as well as its restoration. In 2017, a row of five Baltimore rowhouses within a local historic district were slated for demolition, with three of the buildings clad in Formstone. The staff of Baltimore’s Commission for Historical and Architectural Preservation reviewed the application and determined that the buildings did not contribute to the local district, as too much of the original material had been lost, and recommended demolition. When the issue came in front of the commissioners, a commissioner overruled the staff recommendation. Gesturing to an image of the row of buildings slated for demolition, the commissioner declared, referencing a character in the 1988 John Waters film Hairspray, “That picture. That’s Baltimore! The only thing that is missing is Tracy Turnblad!” The buildings received a stay from demolition.¹¹

Acknowledgements

The author would like to thank the Association for Preservation Technology Building Technology Heritage Library.